This core has two functions and serves all four Projects:[unreadable] 1. Central Facility: This section of the Core is for maintenance, record keeping, and procurement of[unreadable] animals for the four projects. The Core will maintain all surgical records. The personnel associated with[unreadable] the Core will perform ordering, shipping and handling of the rats and transgenic mice. Personnel[unreadable] employed by the Biologic Resources Laboratory (BRL) will be responsible for feeding, watering, and[unreadable] cage cleaning (per diem costs included in budget, see Table 1). Any post-operative complications[unreadable] resulting from the animal surgeries will be addressed by consultation of Core personnel with the[unreadable] veterinary staff at the BRL. Data obtained from the physiological and echocardiographic measurements[unreadable] of the animals will be analyzed and summarized by the Core personnel and presented to the individual[unreadable] project principal investigators. 2. Animal Model and Cardiac Analysis Facility: This section of the core[unreadable] will provide surgical models of transverse aortic banding (pressure overload), aorta-cava fistula (volume[unreadable] overload), and coronary artery ligation (myocardial infarction) in rats, and transverse aortic banding in[unreadable] mice. Core personnel will also instrument rats and mice for measurements of left ventricular[unreadable] hemodynamics using a Millar pressure/volume catheter. Pressure/volume curves will be constructed[unreadable] under baseline conditions and subsequent to inotropic challenges with beta- and alpha-adrenergic[unreadable] agonists. The Core will also perform 2-dimensional and M-mode echocardiography and Doppler aortic[unreadable] and pulmonary flows on mice and rats, before and after surgery, to demonstrate changes with cardiac[unreadable] remodeling and confirm any changes in contractile performance of the[unreadable] heart as assessed by pressure/volume measurements.